NIOSH Director John Howard says, "These recommendations represent the kind of science-based guidance that our partners have requested as a vital component for supporting the safe growth of nanotechnology and U.S. leadership in the global market." The agency reports that engineering controls are favored over administrative and/or PPE for lowering exposure because they remove the hazard at the source before it comes into contact with the worker. In addition, the recommendations fill a void for science-based guidance that people can apply now, while research continues.